How to read a natal chart

There are two primary styles of drawing natal charts, each popular in different regions of India and each offering a unique layout to depict the planetary positions and house divisions.

North Indian Style
Also known as the "Diamond chart" or "Bhaav Chakra," the North Indian chart is characterized by its unique diamond-shaped house structure.
The chart is always square with the houses arranged in a fixed diamond-shaped pattern. The first house of Ascendant is at the top center (looking like an inverted triangle), and the houses are numbered clockwise. Each of the 12 segments represents a house.
The signs are not fixed in the houses and change depending on the Ascendant. The planets are placed according to the house they occupy in relation to the Ascendant. This style focuses more on the houses and their relationship with the planets rather than the signs.
This style is widely used in Northern parts of India and is particularly favored for its focus on house dynamics and ease of reading planetary aspects and house lordships.

South Indian Style
The South Indian style is known for its square chart with sign fixed in place. This style is distinctively different in its presentation.
The chart is divided into 12 square or rectangular segments, each representing a house, arranged in a 4x3 grid. Houses are flexible, depending on the sign of the Ascendant.
Each segment is fixed for a specific sign in a sequential, zodiacal order starting from the Ascendant. The planets are placed in the signs according to their positions at the time of birth.
This style is predominantly used in the Southern parts of India. It is particularly appreciated for its clarity in showing the zodiac signs and for straightforward calculations regarding sign aspects and transitions.

Both styles serve the same purpose of depicting planetary positions and house placements for astrological interpretation, but they do so in visually different ways. The majority of astrologers use both representations, depending on what chart aspect they specifically want to understand.